Scope 1 emissions are the greenhouse gases a company produces directly from sources it owns or controls

Scope 1 covers only the emissions that come straight from a facility or vehicle your company owns. A manufacturing plant's furnace, a delivery truck's engine, a refrigeration system at a warehouse — those are Scope 1. The company itself is the source of the pollution, not a supplier or contractor.

This is the narrowest of the three emissions scopes. It does not include electricity you buy from the grid, emissions from contractors working on your behalf, or the carbon footprint of products your customers use. Scope 1 is what happens on your property or in your equipment, measured in metric tons of carbon dioxide equivalent (CO2e) per year.

The reason companies separate Scope 1 from the other two is control. You can replace a furnace or switch fuel types. You cannot unilaterally change how the power plant generates your electricity. Regulators and investors want to see what a company can actually change, and Scope 1 is where that lever exists.

Key Takeaways

  • Scope 1 includes only emissions from equipment and vehicles the company owns or operates directly, such as boilers, generators, company vehicles, and refrigerants.
  • Common Scope 1 sources are natural gas for heating, diesel or gasoline for fleet vehicles, and fugitive emissions from leaks in pipes or storage tanks.
  • Scope 1 is the smallest of the three emissions scopes but often the easiest for a company to reduce through equipment upgrades or fuel switching.
  • Calculating Scope 1 requires tracking fuel purchases, vehicle mileage, and refrigerant refills, then multiplying by published emissions factors from the EPA or similar bodies.

Common sources of Scope 1 emissions

The largest Scope 1 source for most companies is stationary combustion — burning fuel in boilers, furnaces, generators, or heaters that stay in one place. Natural gas is the most common fuel, but some facilities still use heating oil, propane, or coal. Each has a different emissions factor, meaning the same amount of energy produces different amounts of CO2e depending on the fuel type.

Mobile combustion is the second major category: company-owned vehicles. This includes delivery trucks, service vans, forklifts, and company cars. The emissions depend on fuel type (gasoline, diesel, or compressed natural gas), miles driven, and the vehicle's efficiency. A fleet of 50 delivery trucks can easily produce hundreds of metric tons of Scope 1 per year.

Fugitive emissions are leaks and releases that are not intentional but happen during normal operation. Refrigerant escaping from an air conditioning system, methane leaking from a natural gas pipeline, or propane venting during tank refilling all count. These are harder to measure than fuel purchases, so companies often use industry-standard leak rates rather than direct measurement.

Process emissions come from chemical reactions, not combustion. A cement plant releases CO2 as part of making cement. A wastewater treatment facility produces methane. These are less common than fuel burning but can be very large for certain industries.

How companies measure Scope 1

The standard method is to multiply fuel consumption by an emissions factor — a number published by the EPA, the Intergovernmental Panel on Climate Change (IPCC), or industry groups that says how much CO2e is produced per unit of fuel burned. One gallon of diesel produces roughly 10.15 kg of CO2e. One therm of natural gas produces roughly 5.3 kg of CO2e. These factors are based on the carbon content of the fuel and the efficiency of combustion.

A company tracks fuel purchases from utility bills and fuel delivery receipts. For vehicles, it tracks mileage and fuel type. For refrigerants, it tracks refills and any documented leaks. Then it multiplies each quantity by the appropriate emissions factor and sums the total.

The accuracy depends on the quality of the data. A company with detailed fuel records and vehicle telematics can calculate Scope 1 quite precisely. A company that estimates mileage or uses average fuel prices instead of actual consumption will have more uncertainty. Most companies report a range or a confidence level alongside their Scope 1 number.

The Greenhouse Gas Protocol, published by the World Resources Institute and the World Business Council for Sustainable Development, is the standard framework most companies follow. It specifies which sources count as Scope 1, which emissions factors to use, and how to handle edge cases like leased equipment or contractor-operated vehicles.

Why Scope 1 matters to investors and regulators

Scope 1 is the emissions a company can control most directly. Replacing a gas furnace with a heat pump, switching a fleet to electric vehicles, or fixing leaks in a refrigeration system are all within a company's power. Investors and regulators use Scope 1 to assess whether a company is serious about reducing its carbon footprint, because these are the easiest wins.

Regulators in some jurisdictions now require companies to report Scope 1 emissions or set reduction targets. The Securities and Exchange Commission (SEC) has proposed rules requiring public companies to disclose Scope 1 and Scope 2 emissions in their annual filings. The EU's Corporate Sustainability Reporting Directive requires large companies to report all three scopes. These rules are still being finalized in many places, but the trend is toward mandatory disclosure.

Investors use Scope 1 data to compare companies in the same industry. A cement manufacturer with lower Scope 1 per ton of cement produced is managing its emissions better than a competitor with higher Scope 1. This can affect stock price, access to capital, and insurance costs.

Scope 1 reduction strategies

The most direct approach is fuel switching. Replacing natural gas with renewable energy sources like solar or wind eliminates Scope 1 from that source entirely. Switching a diesel fleet to electric vehicles or compressed natural gas reduces emissions per mile. Replacing a coal-fired boiler with a gas boiler cuts emissions by roughly half for the same heat output.

Energy efficiency reduces the amount of fuel needed. Better insulation, LED lighting, high-efficiency motors, and optimized HVAC systems all lower fuel consumption and therefore Scope 1. These upgrades often pay for themselves through lower utility bills over time.

Leak detection and repair programs can reduce fugitive emissions significantly. Regular inspections of refrigeration systems, natural gas pipelines, and storage tanks catch leaks early. Some companies use infrared cameras or methane detectors to find leaks that would otherwise go unnoticed.

Process changes can eliminate emissions at the source. A manufacturing facility might redesign a process to avoid a high-emission step, or switch to a lower-carbon raw material. These changes often require capital investment and process redesign, so they are less common than fuel switching or efficiency upgrades.

Scope 1 versus Scope 2 and Scope 3

Scope 2 covers emissions from purchased electricity, steam, heating, and cooling. When you buy power from the grid, the power plant that generates it produces emissions — but you did not burn the fuel yourself. Scope 2 is indirect but still within your control in the sense that you can choose a renewable energy supplier or install solar panels to reduce it.

Scope 3 is everything else: emissions from suppliers, contractors, business travel, waste disposal, and the use of products you sell. A software company's Scope 3 might include the emissions from the data centers that run its cloud services. A clothing retailer's Scope 3 includes emissions from manufacturing and shipping the clothes it sells. Scope 3 is often the largest of the three but the hardest to measure and control.

Most companies find Scope 1 easiest to measure and reduce, Scope 2 moderately difficult, and Scope 3 very difficult. Regulators and investors increasingly want to see all three, but they understand that Scope 1 is where a company has the most direct leverage.

Frequently Asked Questions

Does Scope 1 include emissions from contractors or subcontractors?

No. If a contractor operates equipment on your site, those emissions belong to the contractor's Scope 1, not yours. The exception is if you own the equipment and the contractor is just operating it — then it is your Scope 1. The key is ownership and operational control. If you are unsure, the Greenhouse Gas Protocol provides guidance on how to draw that line.

What if my company leases vehicles instead of owning them?

Leased vehicles are typically the lessor's Scope 1, not yours, because the lessor owns them. However, if you have operational control — meaning you decide how and when they are used — some accounting standards allow you to count them as your Scope 1. Check your company's emissions accounting policy or the Greenhouse Gas Protocol for your specific situation.

How often should a company recalculate Scope 1?

Most companies calculate Scope 1 annually, aligned with their fiscal year and financial reporting. Some calculate quarterly or monthly for internal tracking. The frequency depends on how much your operations change and how detailed your reporting needs to be. Annual is the standard for public disclosure.

Can a company offset Scope 1 emissions instead of reducing them?

Offsets can reduce a company's net emissions, but they do not reduce Scope 1 itself. Scope 1 is the actual emissions from your operations. An offset — such as buying carbon credits from a renewable energy project — reduces your total carbon footprint but does not change your Scope 1 number. Regulators and investors increasingly want to see actual reductions in Scope 1, not just offsets.

What is the difference between Scope 1 and carbon footprint?

Scope 1 is one part of a company's carbon footprint. Carbon footprint usually means all three scopes combined. A company might have a Scope 1 of 500 metric tons, Scope 2 of 1,000 metric tons, and Scope 3 of 10,000 metric tons, for a total carbon footprint of 11,500 metric tons. Scope 1 alone does not tell the whole story.